If $A$ is any set, then
$A \cup A' = \phi $
$A \cup A' = U$
$A \cap A' = U$
None of these
Taking the set of natural numbers as the universal set, write down the complements of the following sets:
$\{ x:x\, \ge \,7\} $
If $n(U)$ = $600$ , $n(A)$ = $100$ , $n(B)$ = $200$ and $n(A \cap B )$ = $50$, then $n(\bar A \cap \bar B )$ is
($U$ is universal set and $A$ and $B$ are subsets of $U$)
Let $\mathrm{U}$ be universal set of all the students of Class $\mathrm{XI}$ of a coeducational school and $\mathrm{A}$ be the set of all girls in Class $\mathrm{XI}$. Find $\mathrm{A}'.$
Draw appropriate Venn diagram for each of the following:
$A^{\prime} \cup B^{\prime}$
Let $A$ and $B$ be two sets then $(A \cup B)' \cup (A' \cap B)$ is equal to